diff --git a/dotscape b/dotscape
index 42651f6..87b289c 100755
Binary files a/dotscape and b/dotscape differ
diff --git a/fcore/app-init.sml b/fcore/app-init.sml
index c0635a1..4a1b4d9 100644
--- a/fcore/app-init.sml
+++ b/fcore/app-init.sml
@@ -48,6 +48,8 @@ struct
       , b = 0
       , a = 1
       , modalNum = 0
+      , undo = []
+      , redo = []
       }
     end
 
diff --git a/fcore/app-type.sml b/fcore/app-type.sml
index bb4d0eb..cac39c3 100644
--- a/fcore/app-type.sml
+++ b/fcore/app-type.sml
@@ -34,5 +34,7 @@ struct
     , b: int
     , a: int
     , modalNum: int
+    , undo: square list
+    , redo: square list
     }
 end
diff --git a/fcore/app-with.sml b/fcore/app-with.sml
index 349d74d..4aa5810 100644
--- a/fcore/app-with.sml
+++ b/fcore/app-with.sml
@@ -27,6 +27,8 @@ struct
         , b
         , a
         , modalNum
+        , undo
+        , redo
         } = app
 
       val squares =
@@ -62,6 +64,8 @@ struct
       , b = b
       , a = a
       , modalNum = modalNum
+      , undo = undo
+      , redo = redo
       }
     end
 
@@ -90,6 +94,8 @@ struct
         , b
         , a
         , modalNum
+        , undo
+        , redo
         } = app
     in
       { mode = mode
@@ -114,6 +120,8 @@ struct
       , b = b
       , a = a
       , modalNum = modalNum
+      , undo = undo
+      , redo = redo
       }
     end
 
@@ -142,6 +150,8 @@ struct
         , b
         , a
         , modalNum
+        , undo
+        , redo
         } = app
     in
       { mode = mode
@@ -166,6 +176,8 @@ struct
       , b = b
       , a = a
       , modalNum = modalNum
+      , undo = undo
+      , redo = redo
       }
     end
 
@@ -194,6 +206,8 @@ struct
         , b
         , a
         , modalNum
+        , undo
+        , redo
         } = app
 
       val (xClickPoints, yClickPoints) =
@@ -222,6 +236,8 @@ struct
       , b = b
       , a = a
       , modalNum = modalNum
+      , undo = undo
+      , redo = redo
       }
     end
 
@@ -250,6 +266,8 @@ struct
         , b
         , a
         , modalNum
+        , undo
+        , redo
         } = app
     in
       { mode = mode
@@ -274,6 +292,8 @@ struct
       , b = b
       , a = a
       , modalNum = modalNum
+      , undo = undo
+      , redo = redo
       }
     end
 
@@ -302,6 +322,8 @@ struct
         , b
         , a
         , modalNum
+        , undo
+        , redo
         } = app
     in
       { mode = mode
@@ -326,6 +348,8 @@ struct
       , b = b
       , a = a
       , modalNum = modalNum
+      , undo = undo
+      , redo = redo
       }
     end
 
@@ -354,6 +378,8 @@ struct
         , b
         , a
         , modalNum
+        , undo
+        , redo
         } = app
     in
       { mode = newMode
@@ -378,6 +404,8 @@ struct
       , b = b
       , a = a
       , modalNum = modalNum
+      , undo = undo
+      , redo = redo
       }
     end
 
@@ -406,6 +434,8 @@ struct
         , b
         , a
         , modalNum
+        , undo
+        , redo
         } = app
     in
       { mode = mode
@@ -430,6 +460,8 @@ struct
       , b = b
       , a = a
       , modalNum = modalNum
+      , undo = undo
+      , redo = redo
       }
     end
 
@@ -458,6 +490,8 @@ struct
         , b
         , a
         , modalNum
+        , undo
+        , redo
         } = app
     in
       { mode = mode
@@ -482,6 +516,8 @@ struct
       , b = b
       , a = a
       , modalNum = modalNum
+      , undo = undo
+      , redo = redo
       }
     end
 
@@ -510,6 +546,8 @@ struct
         , b
         , a
         , modalNum = _
+        , undo
+        , redo
         } = app
     in
       { mode = mode
@@ -534,6 +572,8 @@ struct
       , b = b
       , a = a
       , modalNum = newNum
+      , undo = undo
+      , redo = redo
       }
     end
 
@@ -562,6 +602,8 @@ struct
         , b
         , a
         , modalNum
+        , undo
+        , redo
         } = app
 
       val r = modalNum
@@ -588,6 +630,8 @@ struct
       , b = b
       , a = a
       , modalNum = 0
+      , undo = undo
+      , redo = redo
       }
     end
 
@@ -616,6 +660,8 @@ struct
         , b
         , a
         , modalNum
+        , undo
+        , redo
         } = app
 
       val g = modalNum
@@ -642,6 +688,8 @@ struct
       , b = b
       , a = a
       , modalNum = 0
+      , undo = undo
+      , redo = redo
       }
     end
 
@@ -670,6 +718,8 @@ struct
         , b = _
         , a
         , modalNum
+        , undo
+        , redo
         } = app
 
       val b = modalNum
@@ -696,6 +746,8 @@ struct
       , b = b
       , a = a
       , modalNum = 0
+      , undo = undo
+      , redo = redo
       }
     end
 
@@ -724,6 +776,8 @@ struct
         , b
         , a = _
         , modalNum
+        , undo
+        , redo
         } = app
 
       val a = modalNum
@@ -750,6 +804,8 @@ struct
       , b = b
       , a = a
       , modalNum = 0
+      , undo = undo
+      , redo = redo
       }
     end